The effect of adult feeding on female pre-calling period and ovarian development in a migratory moth, the Oriental armyworm Mythimna separata (Lepidoptera: Noctuidae)

Abstract

AbstractFemale oriental armyworm moths, Mythimna separata (Walker), emerged without discernible oocytes in the ovarioles, and reproductive maturity, on the criterion of onset of calling behaviour, was associated with an intermediate stage of oocyte development. Ingestion of carbohydrate was required for completion of oocyte development in the majority of females although a proportion matured when allowed only water. Among females kept alone, these were exclusively moths from a strain selected for early onset of calling but, in the presence of a male, a few females from an unselected line also called and achieved oocyte maturation, without access to carbohydrate. Thus factors other than ovarian development apparently influence the commencement of calling. The absence of an effect of carbohydrate uptake on pre-calling period supports a previous conclusion that this trait is determined primarily by genetic components in this species. It is concluded that ingestion of carbohydrate is important for the attainment of reproductive maturity in M. separata but that it has a differential effect in early and later-calling genotypes. The implications of the results for the reproductive and migratory strategies of M. separata, an important agricultural pest, are discussed.